1. Field of the Invention
The present invention relates to a video display device and an interpolated image generation circuit, and more particularly to a video display device and an interpolated image generation circuit that generate an image of an interpolated frame based on images of respective frames acquired from a broadcast signal.
2. Description of the Background Art
Conventionally, in order to improve the problems of a liquid crystal display television such as the blurring in a moving picture, for example, there is a technique in which a video is displayed at a frame rate higher than that of a video source by generating an interpolated frame (see patent document 1 (Japanese Laid-Open Patent Publication No. 2005-6275), for example). Generally, when generating an interpolated frame, a motion vector is searched for in the unit of a block based on images of frames immediately preceding and following an interpolated frame to be generated, so as to generate an image of the interpolated frame by using the motion vector.
In digital broadcast, video contents of various types are distributed in various forms. For example, the video contents to be broadcast have various types, and movement (change) of images is vigorous in some video contents such as a sport program, while in others, there is little movement of images. Furthermore, in digital broadcast, there may be a case where a frame rate of a video source tote distributed is different from the actual number of frames included in the video content. Specifically, in the case of a movie content, there may be a case where the same image may be consecutively used during two or three frames, thereby distributing a video having 24 frames per second as a video source having 60 frames per second. Still furthermore, among video sources to be distributed via digital broadcast, there may be a video source in which a size of a moving picture (aspect ratio) is 16:9, or there also may be a video source in which a fixed image (side panel) is attached to each of the left and right sides of a moving picture having a size of 4:3.
As described above, in digital broadcast, the video contents of various types are distributed in various forms. Thus, in the case where a frame interpolation process is performed, it may be considered that a content of an appropriate frame interpolation process is different depending on a content of a video source, the distribution form used for the video source, and the like. Therefore, for some video sources, the frame interpolation process may be inappropriate if the same content of the frame interpolation process is performed on all video sources, and thus a proper interpolated frame may not be generated.